A ski boot of this type is described by French Patent No. 2,536,965, in reference to FIG. 2 of this document, and presents the interest of allowing its user either to place the collar and the cap in open rod position and the tarsal support casing in retraction position to put the boot on or remove it, or to place the cap and the collar in position pressing against the leg and the tarsal support casing in position pressing against the foot to ensure the maintenance of the boot while skiing, through this user's action on the single means, namely on the means of traction on the flexible brace, itself acting at once on the tarsal support casing and on the collar and the cap constituting the rod.
In the case of the boot illustrated in FIG. 2 of French Patent No. 2,536,965 and described in reference to this Figure, the means of traction on the flexible brace are comprised of a lock lever, placed around an axis which is approximately vertical on the collar and with numerous anchoring points for the fourth section of the flexible brace; this fourth section presents the form of a loop and, between this fourth section and its second end, the flexible brace presents a fifth section bypassing the cap through the rear, outside the boot, and the second end of the flexible brace is anchored on the collar in a first lateral zone of the boot, at a level close to that of the opening provided for the passage of the second section; for this anchoring of the second end of the flexible brace, the collar, like the lever, presents multiple anchoring points; by choosing the anchoring point utilized on the lever and the anchoring point utilized on the collar, one can adjust the useful length of the flexible brace between its anchoring on the lever and the anchoring of its first end, i.e., the pressing position of the cap and the collar against the leg and the pressing position of the tarsal support casing on the heel of the foot, as well as the pressure which the cap and the collar on one hand, the tarsal support casing on the other hand, apply respectively to the skier's leg and kick portion of the foot in these respective positions.
Such a design presents the inconvenience of implementing a flexible brace with a long total length, measured between the two ends of the flexible brace, and of releasing this great length of the flexible brace when one places the cap and the collar in open position and the tarsal support casing in retraction position, notably, with the risks of tangling and hindrance for the user in putting the boot on or removing it; this inconvenience is all the more sensitive since French Patent No. 2,536,965 recommends, in reference to its FIG. 2, a bypassing of the relative pivoting axis of the cap and of the collar by the flexible brace between its first section, working together with the tarsal support casing and its second section crossing the collar.
In addition, the mode for adjusting the useful length of the flexible brace, defined above, by anchoring on the point appropriately chosen among numerous points respectively on the locking lever and on the collar, is revealed as inconvenient and does not necessarily result in the obtention of a pressing position of the cap and the collar against the leg, on one hand, a position of the tarsal support casing exerting pressure on the foot, on the other hand, which are completely satisfactory for all conformations of the leg and foot.